Video: More building and comparing wholes from different unit fractions

﻿Hello, it's Mr. Johnson here again, and I'll be working with you with this lesson. But first of all, we're going to look at the problem that I sent you at the end of the last lesson. Now, it was tricky, so I'm sure I'm going to be impressed with your understanding. So, I said to you, I wanted to know what fraction of the whole was orange? Right, so when we look at this, the problem that we have is that the parts are not equal. So, was there anything that we could do? When I look at the two pieces here, and I've got a small triangle. Now, if I take that small triangle, I can fit it into that gap. Oh, is there something that I could do with the two smaller orange rectangles? That's right, I could put them together, and make another part that is shaded. So now, let's look at our sentence stem. So, there are how many equal parts in the whole? There are six equal parts in the whole. How many parts are shaded? Well, now, we can see that three parts are shaded. So, altogether, we have got 3/6 is shaded. I'll be really impressed if you got that 'cause that was tricky. So, well done for trying that. And that was how we could have worked that out. So, let's look at this image together that we've seen in previous lessons. What do you notice about the number of sixths? Just something to think about and let's have a go at trying to fill in the sentence stem together. So, the whole has been divided into equal parts. So, how many equal parts are in the whole? There are six, so let's say that together now. The whole has been divided into six equal parts. The next part of our sentence stem, so hmm of the parts are shaded. How many parts are shaded? There are five of the parts shaded, so let's say that together. Five of the parts are shaded. And our last part of our sentence stem, there are five 1/6 shaded. Now, we have the same image as before but this time, I would like you to have a go at writing down what this is as a fraction. So, how would I write five 1/6 as a fraction? Think about which numbers you would use, and where you're going to place them in relation to the division bar. So, have a try now, so pause the video and have a go. Now, let's see if I agree with you. So, the whole has been divided, so we would place our division bar. And the whole has been divided into six equal parts, so we would put our six underneath the division bar. And five of the parts are shaded, so that would go above the division bar, just like I've got here. So, well done if you got that right. Now, it's great being able to write some numbers down, but if you don't understand where the numbers have come from, then it's not going to help you in future lessons. So, let's look at these numbers. First of all, what does the six represent? Why don't you quickly whisper to somebody what you think it means. That's right, the whole has been divided into six equal parts, so that's where the number six comes from. What about the five, what does that represent? The five is the number of parts that are shaded. So, altogether, this is 5/6 of the whole. Now, let's look at this next image together, which is a circle. Let's look at our stem sentences, and see if we can complete them. So, the whole has been divided into equal parts. So, what number would go in there? So, let's now read it together, and see if we can fill in that blank. So, the whole has been divided into three equal parts. The next part of our stem sentence, so blank of the parts have been shaded. So, let's say it together, filling in the blank. Two of the parts have been shaded, so we can say there are two 1/3. Now, we have the same image again but this time, I want to know how do we write two 1/3 as a fraction? So, the whole has been divided, so that tells us we need our division bar again. And it's been divided into three equal parts, so that means our three goes underneath our division bar. And two of the parts are shaded, so we can say that 2/3 of this shape has been shaded. So now, I've got an activity I would like you to do. So, this time, I have got an image where some of the parts are shaded, and I would like you to fill in the sentence stem below and then try to write a fraction as well. So, pause the video and have a go. So, let's see how you've done. So, this was the image that I have given you. The whole has been divided, so that means you should have done your division bar. So, the whole has been divided into five equal parts, so the number five should have been put underneath the division bar. And three of the parts are shaded, so your three should be above the division bar. So, that is 3/5 of the whole has been shaded, well done. Now, let's look at this problem together. So, this time, I've given you the image, and I've given you the fraction. And we've got to try and fill in the missing numbers into our stem sentence. So, let's look at the first part of our stem sentence. So, the whole has been divided into blank equal parts. Let's look at our image. So, our image shows that the whole has been divided into two equal parts, but let's look at our fraction. Oh, now, they're both two. So, which of those twos tells us that the whole has been divided into two equal parts? Quickly whisper to somebody and tell them. Right, it's the two underneath the division bar because that tells us that the whole has been divided into two equal parts. Let's look at the next part of our stem sentence. So, blank of the parts are shaded. Hmm, how many parts are shaded? So, when we look at our image, first of all, we can see that two of the parts are shaded. Now, which of those twos tells us that two of the parts are shaded in our fraction? It's the two on top of the division bar 'cause that tells us that two of the parts are shaded. So, that tells us, altogether that 2/2 of the whole has been shaded. I now have another practise activity I'd like you to have a try at. So, I have the written fraction, which is 3/4. And what I would like you to do is to draw your own whole to show 3/4 shaded. I want you to think about how many equal parts you will need to divide your whole into, and how many parts will need to be shaded. So, I'd like you to pause the video and have a try. So, let's see how you've done. I'm going to show you some examples of what 3/4 could look like. It might not look exactly the same as yours, but they should have something that is the same. So, here are my examples. That was one, two and three. What did your image look like? Now, let's look at this stem sentence and complete it. So, 3/4 equals how many 1/4? So, that would be three 1/4. Well, let's think about these numbers in our fraction. What does the four represent? What does the three represent? Well, the four is how many equal parts the whole was divided into. So, in your image, there should have been four equal parts. And what does the three represent? The three represented how many parts were shaded. Count how many you shaded in. Was it three? Let's look at 3/4 again but this time, we've got a sentence stem that can help us. So, the sentence stem tells us that the whole has been divided into four equal parts, so we can see the four. And it also tells us that three of the parts are shaded, and we can see where the three is. So, that is 3/4 of the whole. So, let's look at my pictures, and use our sentence stem just to make sure. So, in our triangle, the whole was divided into four equal parts and three of the parts are shaded, so that is 3/4 of the whole. Let's look at this image and check. So, the whole has been divided into how many equal parts? Four equal parts and three of the parts are shaded. So, that is 3/4 of the whole. In my final image, my whole was split into four equal parts, and three of the parts are shaded, so what's that fraction? That's right, it's 3/4. Now, I want you to look at your image that you drew, and use the sentence stem to check that it was right. Here is your challenge that you will need to have a try at before the start of the next lesson. So, in this problem, a whole orange was shared between two children. And the plates show you how much of that orange each child got. So, I would like to know what fraction of the orange did Pawel get, and what fraction of the orange did Dominika get? So, good luck with this challenge. And remember, just keep practising your skills, goodbye.

Lesson summary: More building and comparing wholes from different unit fractions

In this lesson, we build and compare different wholes from different unit fractions that represent different quantites.

Maths

Y4 Maths

Key Stage 2

Year 4

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Repeated addition of unit fractions

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Fractions equal to one whole

Beginning to compare non-unit fractions

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Maths

More building and comparing wholes from different unit fractions

Video

Lesson summary: More building and comparing wholes from different unit fractions

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